"Side Effects," the latest work from the seemingly inexhaustible Steven Soderbergh, is one of those movies that starts off telling one kind of story only to abruptly shift gears at a certain point in order to tell a completely different one. The trouble is that the first story is by far the more interesting of the two while the second just becomes more implausible with each passing scene. The end result is a film that is certainly watchable enough but which never quite manages to live up to the promise of those intriguing opening scenes.

As the film opens, the focus is on Emily Taylor (Rooney Mara, divested of all her "Dragon Tattoo" accoutrements), a young woman who is anxiously awaiting the return of husband Martin (Channing Tatum) after a four-year prison stretch for insider trading. The two still love each other and Martin is making a sincere effort to get them back to where they were before his incarceration but the pressures brought on by his return and lack of employment, their money woes and her ongoing struggles with anxiety and depression lead to an incident that lands her in the hospital.

There, she is treated by psychiatrist Dr. Jonathan Banks (Jude Law), who prescribes a wide variety of the usual pharmaceutical suspects--Prozac, Zoloft and the like--to help her get a hold of her symptoms but while she manifests many of the side effects that come with the medications (sleepwalking, increased sex drive and the like), none of them seem to actually be helping her. Banks eventually consults Emily's former therapist, Dr. Victoria Siebert (Catherine Zeta-Jones), and she suggests trying a new drug on the market known as Ablixa that might be able to help.

It is at this point that the story takes its big unanticipated twist, though viewers who recognize the source of the film's opening shot may have a leg up on guessing what is coming. Suffice it to say, Emily's use of Ablixa has unanticipated side effects not only for her but for Banks and Martin as well and the story becomes a puzzle in which nothing is quite as it seems. In other words, if you want to see this movie and know someone who love to blurt out spoilers, stay away from them until you have seen it for yourself.

The early scenes of "Side Effects" are fairly spellbinding in the way that Soderbergh quietly but effectively puts viewers into the jagged and anxious mindset off someone who is feeling out of sync with the world around them and who is seemingly helpless to do anything about it. At the same time, he and screenwriter Scott Z. Burns (who previously collaborated on "The Informant" and "Contagion") offer a cuttingly satirical glimpse at an overmedicated world in which doctors serve as paid mouthpieces for pharmaceutical companies and everyone has a recommendation for some pill or another that will presumably eradicate those pesky traces of everyday existence.

This stuff is all great but it all gets shoved to the side once the focus of the story gets shifted. Without going into too much detail, it appears that Burns took all of the melodramatic plot developments that he smartly left out of his screenplay for "Contagion" (another film with a dim view of the pharmaceutical industry) and stuck them in here instead. The initially fascinating characters soon find themselves prisoners of a narrative that gets more and more unlikely with each passing scene until it finally devolves into something virtually indistinguishable from a episode of one of the lesser "Law & Order" spinoffs. For viewers who found themselves hooked by the opening scenes, this conclusion will no doubt come as a crushing disappointment.

And yet, even though "Side Effects" is largely lacking the distinctive personal touch that he has managed to bring even to such nakedly commercial propositions as "Ocean's 12," "Haywire" and "Magic Mike," he keeps things humming along in a reasonably smooth and efficient manner. Serving once again as his own cinematographer under his Peter Andrews pseudonym, it has an arresting visual style that catches the eye throughout and he gets good performances from his lead actors--if nothing else, the film offers Channing Tatum another chance to prove that there is a strong and capable actor lurking behind the hunky heartthrob exterior. This may not go down as one of Soderbergh's better films by a long shot but his efforts make it far more watchable than it might have turned out to be in other, lesser hands.

"Side Effects" has enough good things going for it to keep it from being dismissed completely but they are offset by enough flaws to prevent a wholehearted recommendation. In the end, the most interesting thing about it is the fact that Soderbergh, who has been averaging 1-2 movies a year for the last few years, has hinted that he would be retiring from feature filmmaking (or at least taking a long hiatus) in order to explore options like cable television (where his next effort, a biopic on Liberace with Michael Douglas and Matt Damon, will be premiering this spring) that would allow him to do the projects that he wants that fall outside of the Hollywood blockbuster mentality.

I have no doubt of Soderbergh's sincerity in regards to this but I have the sneaky suspicion that his "retirement" will probably last as long as Frank Sinatra's did. If nothing else, I find it difficult to believe that a filmmaker whose career has featured as many high points as anyone else working today would want to pull a Gene Hackman and go out with something that is nowhere near his best or most lasting works as the actor did by apparently bowing out with the aggressively mediocre "Welcome to Mooseport." My guess is that Soderbergh will take a break from filmmaking for a couple of years and let the batteries recharge and after that happens, he will return anew with the kind of complex and intelligent entertainments that he is capable of delivering and "Side Effects" will come to be thought of as a minor side effect to an otherwise sterling career itself.